The invention is situated in the field of materials handling technology and is related to a device serving for the transfer of flat articles being supplied one after the other (serially) to a conveying-away system, wherein the device takes over the articles from a supply device, conveys them onwards in a take-over direction and during conveyance in a transfer direction transfers them to the conveying-away system.
Devices of the type mentioned are used, for example, for gathering printed products into product groups to be further processed as units. For such gathering, various types of printed products are supplied to a feed point each, for example from stacks by means of feeders, from rolls by means of winding stations and/or continuously in the form of streams of imbricated products. The product groups to be formed by gathering are conveyed one after the other past a plurality of feed points, wherein at each feed point one printed product is added to each one of the product groups being conveyed past, for example from above or from below. If the product groups being such created are conveyed continuously, a problem-free transfer at every feed point is possible only if the products are conveyed in substantially the same direction as the product groups being produced, at least immediately preceding the effective transfer. Thereby the conveying direction of the products to be added to the groups approaches the direction of group conveyance e.g. from above or from below.
An installation as briefly described above serving for gathering printed products comprises a plurality of supply devices (e.g., feeders, winding stations, devices for conveying imbricated product streams, etc.), a device for conveying product groups being created and for each feed point one transfer device taking over the products from the supply device and transferring them to the product groups being created. The transfer devices can also be integrated in the supply devices or in the device for conveying the product groups.
Such installations should fulfil the most varied requirements, for example:
the installation should be as simple as possible (conveying movements being as simple as possible and continuous);
the installation should allow conveyance in as dense as possible conveying streams both for the products to be supplied and the groups being created (conveying speeds as low as possible);
the installation should require as little space as possible and should have as short as possible transfer paths between the supply devices and the feed points (supply devices located as close as possible together and as close as possible to the feed points);
the installation should allow transfer of the products without significant change of their orientation relative to the conveying direction.
These requirements are fulfilled by known installations in different ways and to a greater or lesser degree.
In installations with a drum-shaped conveying device, in which product groups being created are conveyed continuously in radial direction and stepwise in axial direction, it is easily possible to have dense conveying streams, equal product orientations for product supply and group conveyance as well as a space-saving arrangement of supply devices and short transfer paths between supply device and feed point (transfer paths extending in one plane only). The drum-shaped conveying device, however, is a rather complicated device as such. About the same is valid for installations with linear conveying devices, in which straight line, continuous group conveyance in a main conveying direction is superimposed by a further, stepwise conveyance transverse to the main conveying direction.
Installations, in which group conveyance is continuous and forms an essentially straight line, also render dense conveying streams possible. A space-saving arrangement of the supply devices along a conveying route of this type, however, makes it necessary, that the transfer paths extend in a three-dimensional manner (transfer paths with an angled plan view layout or with additional lateral displacement). Known devices for conveying the products to be transferred along three-dimensional transfer paths are, for example, twisted pairs of conveyor belts or other conveying devices suitable for a twisted arrangement. Devices of this type are rather elaborate and because of the relatively large bend radii necessary, result in rather long transfer paths. Furthermore, twists by less than 360xc2x0 change the orientation of the products to be transferred relative to the direction of conveyance.
The invention attempts to combine the advantages of the two types of installations as mentioned above, i.e. it attempts to combine a substantially straight-line, continuous conveyance of a dense stream of product groups being created during conveyance past feed points with a space-saving arrangement of supply devices and short, easily implementable transfer paths between supply devices and feed points.
It is therefore, the object of the invention to create a device for transferring flat articles being supplied serially (e.g., printed products to be added to product groups) to a continuous conveying-away system (e.g., conveyance of product groups being created). With this device, the articles are to be taken over from an as such known supply device (e.g., sheet feeder, winding station, continuous feeder), conveyed along a transfer path and from above or from below transferred to an as such known, continuously operating conveying-away device, which defines a conveying-away direction, wherein the transfer path and the conveying-away path represent an angled, three-dimensional path construction. Thereby the transfer path is to be significantly shorter than known three-dimensional transfer path arrangements. The transfer device in accordance with the invention nonetheless is to be simple and it shall make it possible to take over the articles with an orientation relative to the conveying direction and to transfer them with the same orientation relative to the conveying direction.
The device according to the invention comprises a circulating conveying organ and grippers conveyable with the help of the conveying organ, each gripper serving for gripping an edge zone of one flat article. The part of the circulation track of the conveying organ used for conveyance comprises a take-over zone (conveyance in takeover direction) and a transfer zone (conveyance in transfer direction) following the take-over zone after a deflection. The take-over direction and the transfer direction intersect and define a plane of conveyance. For deflecting the conveying organ between take-over zone and transfer zone there is e.g. provided a deflection means rotating around an axis oriented vertically to the plane of conveyance and possibly serving also as a drive means.
The circulation track of the conveying organ is arranged relative to the conveying-away direction of the conveying-away device in the following manner: A transfer plane contains the transfer direction and the conveying-away direction or a parallel thereto, wherein the transfer direction and the conveying-away direction or parallels thereto run towards each other at an acute angle and intersect. The transfer plane stands vertically on a base plane. The take-over direction intersects the transfer plane. There is a take-over plane containing the take-over direction, standing vertical to the base plane and enclosing an angle (e.g., a right angle) with the transfer plane, wherein the transfer direction and the take-over direction intersect in the angle-point of this angle. Transfer direction and take-over direction have different inclinations relative to the base plane (e.g., gradients opposing one another), at least the gradient of the transfer direction being also different from the gradient of the conveying-away direction. This signifies, that the plane of conveyance defined by the transfer direction and the take-over direction is intersected obliquely by the conveying-away direction.
The direction in which the articles are supplied (supply direction) or a parallel thereto extends in preference and dependent on the transfer mode in the take-over plane.
The grippers are arranged on gripper arms laterally protruding from the conveying organ, wherein the gripper arms are oriented vertically to the longitudinal expanse of the conveying organ, therefore vertically to the take-over and transfer direction, and at least locally they extend non-parallel to the plane of conveyance defined by the take-over and transfer direction. The angle between the gripper arms and the plane of conveyance is dependent on the gripper arm orientation relative to the take-over and transfer plane, on the gradients of take-over and transfer direction and on the angle between take-over and transfer plane. The gripper arm orientations relative to take-over and transfer plane is predetermined by the take-over and/or the transfer mode and is e.g. perpendicular, i.e. parallel to the base plane.
If the gripper arm orientations necessary for take-over and transfer are equal and the gradients of the take-over and the transfer directions are opposing and equal, then the angle between the plane of conveyance and the gripper arms is the same for take-over and transfer, i.e., it can be maintained constant over the whole circulation track of the conveying organ. This is applicable for the preferred embodiment of the device according to the invention, in which the gripper arms are arranged in a fixed manner on the conveying organ and the conveying organ does not have to be able to be twisted.
The one part of the circulation track of the conveying organ, which does not serve as active conveying part, can be designed in any way required both with respect to its course as well as with respect to the gripper arm orientation. The device becomes particularly simple, if this inactive part of the circular path extends in the plane of conveyance defined by the take-over direction and the transfer direction and comprises two further deflection means such that the circulation track of the conveying organ substantially represents a flat triangle.
The conveying organ of the device in accordance with the invention is e.g. an endlessly circulating conveyor chain with gripper arms fixedly arranged on its links. If the angle between the plane of conveyance and the gripper arms is to be different for take-over and transfer and therefore has to be adjustable, then the chain links have to be designed to be able to be rotated relative to one another around the conveying direction (twistable chain) and the chain has to be guided within a channel with a slot, wherein the gripper arms protrude from the slot and the position of the slot relative to the direction of conveyance defines the local angle between the gripper arms and the conveying direction. Also conceivable are gripper arms arranged to be capable of being articulated on the chain links of a non-twistable chain, and being controlled by corresponding cam members in a manner to form locally predefined angles with the plane of conveyance.
Instead of a chain conveyor, it is possible to provide a multitude of conveyor elements, which are more or less independent of one another, which carry gripper arms and which are driven in a suitable guide means, for example, by e.g. pushing one another along. Such conveying elements can be designed to either be capable of being rotated around the direction of conveyance or not.
The device according to the invention is applicable in particular for transferring serially supplied flat articles to a device, with the help of which article groups being created by successive article transfer to each group are continuously conveyed one behind the other, wherein in a plane view, the supply direction is e.g. perpendicular to the direction of group conveyance. Thereby it is possible for the planes of conveyance of adjacent transfer devices to overlap one another, so that a really tight arrangement along the group conveying device becomes possible. In the same manner, the device in accordance with the invention can be used wherever flat articles are serially supplied and have to be transferred to a continuous conveying-away system extending at an angle to the supply direction.